How to Configure BranchCache in Windows Server using PowerShell

The Wide Area Network Bottleneck

Consider a large corporation with a primary data center in New York and a small branch office in London. The London office has 50 employees and is connected to New York via a slow, expensive WAN link (e.g., a 50Mbps VPN tunnel). Every time an employee in London opens a massive 500MB corporate training video stored on the New York file server, that 500MB is dragged across the slow transatlantic link. If 10 employees open it simultaneously, the 50Mbps link instantly saturates, and the entire London office loses internet connectivity.

Windows Server solves this natively with BranchCache. BranchCache is a Wide Area Network (WAN) bandwidth optimization technology. When the first employee in London downloads the 500MB video, BranchCache intercepts it and silently caches a copy locally within the London office. When the second employee tries to open the exact same video, Windows realizes it is already cached locally and serves it to them at Gigabit LAN speeds, consuming absolutely zero bandwidth on the transatlantic link.

While this can be deployed via Group Policy, PowerShell is the most effective way to configure the central Content Servers.

Step 1: Installing the BranchCache Feature

You must install the BranchCache feature on the central file server in New York (the Content Server). Open an elevated PowerShell session and execute:

Install-WindowsFeature -Name BranchCache -IncludeManagementTools

Step 2: Enabling Hash Publication

For BranchCache to work, the Content Server must generate cryptographic hashes of its files. When a London client requests a file, the server sends the hash first. The client checks if anyone in London already has a file matching that hash. If they do, they grab it locally; if not, they download it from New York.

You must enable hash generation on the file server:

Enable-BCHashPublication -RootPath "D:\CorporateShares"

This command instructs the server to begin calculating hashes for every document inside the D:\CorporateShares directory.

Step 3: Configuring the BranchCache Mode (Distributed vs. Hosted)

BranchCache operates in two modes.

• Distributed Cache: There is no dedicated server in London. The Windows 10/11 laptops simply share the cached files peer-to-peer among themselves. (Best for very small offices).
• Hosted Cache: You deploy a dedicated Windows Server in London to hold the cache. This is far more robust because laptops can be turned off, but the server is always on.

To configure a small Windows Server in London (LON-SERVER-01) to act as the Hosted Cache, log into that server and execute:

Install-WindowsFeature -Name BranchCache
Enable-BCHostedServer -RegisterSCP

The -RegisterSCP flag is critical. It publishes a Service Connection Point in Active Directory, allowing the Windows laptops in London to automatically discover that LON-SERVER-01 is their designated cache server.

Step 4: Managing Cache Storage Limits

By default, the Hosted Cache server will allocate 5% of its active hard drive for caching. If you have a dedicated 2TB drive (E:) for caching, you should increase this limit to maximize the bandwidth savings.

Execute the following on the Hosted Cache server:

Set-BCCache -Path "E:\BranchCacheStore" -Percentage 80

This moves the cache database to the E: drive and allows it to consume up to 80% of the disk space before it begins pruning older files.

With BranchCache fully deployed, you have effectively eliminated redundant WAN traffic, dramatically improving application performance for remote branch offices.